Aviation turbine fuels are used for powering jet and turbo-prop engine aircraft. There are two main grades of turbine fuel in use for United States civil commercial aviation: Jet A-1 and Jet A, both of which are kerosene-type fuels. Avgas is a gasoline fuel that is used for reciprocating piston engine aircraft. Avgas grades are defined by their octane rating. Two ratings are applied to aviation gasolines: lean mixture and rich mixture ratings. Currently, the two major grades in use are: Avgas 100LL and Avgas 100.
The introduction of turbine fuels into a reciprocating engine can have disastrous consequences. If this happens, the reciprocating engine aircraft will be able to operate for several minutes before a problem is realized. Often, this allows the aircraft to taxi, take off, and climb to significant altitude before engine failure. The severity is easily seen as fatalities directly result from the introduction of the incorrect type of fuel in such aircraft. As such, there is a great need to ensure that the wrong fuel is not introduced into a given type of aircraft.